ZyloxDragon: A trackball mouse. I never could get the hang of moving the pointer with my thumb. I got more quickly adjusted with a HOTAS than those mice.
Maighstir: There are three types of trackball - depending on how they're built, you can control them with the thumb, fingers, or the flat of your hand, I prefer the two latter (even to a "regular" mouse), I've tried a thumb-controlled one (Logitech something?) and pretty much agree with you on that one. At home, I use a Kensington Expert Mouse (flat/fingers), at work I used to use a Microsoft Trackball Explorer (fingers) until it died and I switched to a RollerMouse (fingers/thumb) (not a trackball, more like a trackstick?).
And yes, I play games with the trackball. Even Diablo 2 and Unreal which both require a bit of precision and speed. I'm no worse than with a mouse, then again, I wasn't very good to begin with.
I use a trackball for everything. It is superior to a mouse because it doesn't move, so it doesn't need a pad. I'm not sure why you (both) have trouble using it, since it is perfectly intuitive. Then again, perhaps I'm just a fast learner, since I brush my teeth with either hand.
What about The Woz's paddles? (Steve Wozniak, co-inventor of the Apple pc, who was shafted by Steve Jobs, invented the paddle interface that came in pairs and each was a linear controller. One was used to move vertically and the other horizontally, like the two dials on an Etch-a-Sketch, it that helps.)